thunder
The loud rumbling or crashing sound caused by the rapid expansion of air heated by lightning.
Etymology
From Old English þunor, from Proto-Germanic *þunraz. This traces to PIE *(s)teh₂n- meaning "to thunder, to crash." The Norse thunder god Þórr (Thor) takes his name from this same root. The word shows the characteristic Germanic sound shift from t to þ.
The Journey: *(s)teh₂n- → thunder
*(s)teh₂n-
*þunraz
þunor
thunder
Cognates Across Languages
These words in other languages descend from the same PIE root *(s)teh₂n-. They are not borrowings but independent inheritances from a common ancestor.
| Language | Word |
|---|---|
| Latin | tonāre (to thunder) |
| Celtic | Taranis (thunder god) |
| Sanskrit | stan- (to thunder) |
| Old Norse | Þórr (Thor) |
| Old High German | donar |
Did You Know?
Thursday is literally "Thunder's day," named after the Germanic god Þunor/Thor. Latin tonāre "to thunder" gave English "astonish" (originally "to strike like thunder"), "stun," and "detonate."
This word descends from the Proto-Indo-European root *(s)teh₂n-. See the full root page for descendant trees, sound law references, and scholarly discussion.